1. Field of the Invention
The present invention relates to a method of manufacturing a liquid discharge head (hereinafter, also referred to as “ink jet recording head”), which discharges liquid by applying energy to the liquid, and a method of manufacturing a substrate for a liquid discharge head.
2. Related Background Art
Printers with ink jet recording heads as printing apparatuses have become widely used due to their good printing performance and low costs. Ink jet recording heads such as the one which generates bubbles in ink with thermal energy to discharge ink droplets with pressure waves by those bubbles, and the one which uses pressure waves by vibrators such as a piezoelectric element, etc., have been developed.
Among the above-described ink jet recording heads, the one which uses piezoelectric elements is configured so that when a predetermined voltage is applied to an ink flow path communicated to the ink discharge port, a pressure generating chamber, and a vibration plate thin film piezoelectric element provided for this pressure generating chamber and to which a piezoelectric element thin film is bonded the piezoelectric element thin film is caused to expand and shrink and thereby the piezoelectric member and the vibration plate film oscillate in an integral fashion so that ink inside the pressure generating chamber is compressed and thereby ink droplets are discharged from the ink discharge port.
By forming a piezoelectric element thin film in a single crystal or in a preferential orientation, displacement can be large, and displacement can be controlled linearly to drive a waveform. Japanese Patent Application Laid-Open No. H10-181016 discloses a method of removing a substrate, and implementing transfer onto a vibration plate after a piezoelectric member is formed on a single crystal substrate in single crystal, or is directed in a preferential orientation.
In addition, Japanese Laid Open-Open Patent Application No. 2002-234156 discloses a piezoelectric element structure which comprises a piezoelectric film, a vibration plate and the like configuring the thin piezoelectric element so as to enable micro machining (fine processing) generally used in a semiconductor process, and which is excellent in endurance and piezoelectric property. Japanese Patent Application Laid-Open No. 2002-234156 further discloses a method of forming a piezoelectric element thin film in single crystal or directed in a preferential orientation on a so-called SOI substrate which has undergone lamination of Si single crystal onto an oxidized film.
In the recent years, ink jet recording heads have been considered not only for consumer use in printers which print letters or image information onto paper, but also for use in a field where materials have been coated with a stencil and the like or in industrial fields such as organic EL (Electro Luminescence) and the like where (red-blue-green) organic materials are coated onto a substrate.
In case of use in industrial fields, since process amounts per hour is a parameter directly relating to costs, rapidness is required. In printers for consumer use, functions to discharge fine droplets, endurance and reliability are required.
Japanese Patent Application Laid-Open No. H10-181016 caused a thin film in a single crystal or directed in a preferred orientation to the direction of the polarization, showing a perovskite structure containing a lead zirconate titanate (PZT) system or a barium titanate system as the main component, to grow in a single crystal substrate which was not directly connected with a vibration plate. Thereafter, the substrate was removed so that the vibration plate was bonded. Therefore, it was difficult to produce an ink jet recording head with nozzles disposed with high fineness.
In addition, the process disclosed in Japanese Patent Application Laid-Open No. 2002-234156 can make obtainable a piezoelectric element structure which enables micro machining (fine processing) and is excellent in endurance and piezoelectric property. Moreover, it is desired to produce an ink jet recording head which undergoes the process on a liquid chamber simply, and which is cheap and gives good yield factor and comprises nozzles disposed highly densely.
The ink jet recording head to be used in the present specification does not mean only such a type of head that discharges inks onto paper, but is also used as a collective term of such a type of head that discharges liquid onto an object disposed in a desired location.